Abstract:
Objective: To analyze the influence of meteorological factors and air pollutants on the number of patient visits for upper gastrointestinal bleeding in Baise City.
Methods: Air pollution data, meteorological data and medical information of patients with upper gastrointestinal bleeding in the Affiliated Hospital of Youjiang Medical University for Nationalities from 2017 to 2021 in Baise City were collected.Based on the generalized additive model of Poisson distribution, after controlling the influence of confounding factors, the single pollutant models of air pollutants with daily concentration (lag0) and lag 1-7 d (lag1-lag7) were constructed respectively, and the relative risk, odds ratio and their 95% confidence interval (95%
CI) were calculated.The pollutant concentration corresponding to the highest odds ratio was selected as the optimal lag day concentration, and the bivariate response surface model was used to analyze the single pollutant-temperature interaction model.
Results: There were 1, 391 cases with middle and upper gastrointestinal bleeding.The correlation results between air pollutants and meteorological factors showed that the concentrations of fine particulate matter (PM
2.5), inhaled particulate matter (PM
10), sulfur dioxide (SO
2), nitrogen dioxide (NO
2) and ozone (O
3-8 h) were positively correlated with daily average temperature levels (
P< 0.01), and were negatively correlated with relative humidity and atmospheric pressure (
P< 0.01).The correlation between PM
2.5 and PM
10 was the strongest (
ρ=0.950).Compared with the reference temperature of 20℃, low temperature (7℃) increased the number of patient visits for upper gastrointestinal bleeding in Baise City by 1.25 (95%
CI:1.005 5-2.205 2) and 1.32 (95%
CI:1.001 2-2.986 0) at lag2 and lag6, respectively.PM
2.5, PM
10, SO
2 and NO
2 could lead to 0.34% (95%
CI:1.000 7-1.006 2), 0.26% (95%
CI:1.000 5-1.004 7), 0.86% (95%
CI:1.001 9-1.015 3) and 1.31% (95%
CI:1.005 0-1.021 3) increase in the number of patient visits for upper gastrointestinal bleeding on the optimal lag day, respectively.The results of interaction analysis showed that moderate temperature and high concentration of PM
2.5 had a synergistic enhancement effect on the risk of upper gastrointestinal bleeding (
RERI=0.674, 95%
CI:0.395-0.952).
Conclusion: Low temperature and exposure to PM
2.5, PM
10, SO
2 and NO
2 will increase the risk of upper gastrointestinal bleeding.